Three-dimensional (3D) image display apparatuses are apparatuses that show different two-dimensional (2D) images to a left eye and a right eye of a user, thereby providing a 3D image that enables the user to feel a sense of three dimensions.
The 3D image display apparatuses are classified into a glasses type and a glasses-free type. 3D image display technologies based on the glasses-free type are technologies using directional backlight technology that irradiates backlight in a desired direction.
In a conventional directional backlight technology, a prior art reference (U.S. Pat. No. 8,743,038B2) discloses a directional backlight unit where a plurality of light sources disposed on a rear surface of a liquid crystal display (LCD) panel irradiate backlight (or white light) onto a specific region in a direct type.
In the prior art reference, since a specific region for allowing a user to view a 3D image through the LCD panel is fixed, two eyes of the user should be located in the specific region for viewing the 3D image. This denotes that when the user deviates from the specific region, the user cannot view the 3D image.
Moreover, the LCD panel disclosed in the prior art reference may include a color filter having a thin film type, for extracting three colors including red, green, and blue in units of one pixel by using the backlight (or the white light).
In reproducing a three-color 3D image, the color filter is a necessary element, and is a main element in terms of optical attenuation of the backlight (or the white light).
In another conventional directional backlight technology, another prior art reference (U.S. Patent No. 20120050148A1) discloses backlight technology using an edge type light source array.
The other prior art reference uses different light source arrays for showing images to left and right eyes of a viewer. For this reason, additional light source is needed.
Moreover, in the other prior art reference, even when a viewer is located at a position corresponding to a center of a screen, appropriate images are transferred to left and right eyes of the viewer, and for this reason, a position which enables the viewer to view a 3D image is limited. Also, such a method needs a color filter for RGB color division from backlight, causing optical attenuation of the backlight (or white light).